Abstract: Systems and methods described herein may produce a modified substrate. A process for producing a modified substrate may include providing a substrate that is 5 microns or less in thickness, ion tracking the substrate, and etching the tracked substrate with an etchant to produce a plurality of pores in the substrate. In some implementations, the substrate may be a polymer. In some implementations, the ion tracking may include controlling a flux of ions passing through the substrate to achieve a desired pore density. In some implementations, the track-etching of the substrate may create a 10% or more porosity in the substrate. In some implementations, the process may further include using the track-etched substrate as a support substrate for at least one of a single-layer graphene film, multi-layer graphene film, stack of graphene films, nanostructure of graphene flakes, or nanostructure of graphene platelets.